The hole is a string keeper. The bow is likely not worth the time to attempt putting back in service.
It's either hickory or lemonwood, but from what I could see it looks like lemonwood. Photos are not the easiest to ID wood from. Don't be too hard on me if it turns out to be hickory.
I don't miss many if I can get my hands on the wood.
Hickory is a coarse wood and easy to see where growth rings have been violated. Lemonwood is finer and more difficult to determine violated growth rings.
Both hickory and lemonwood were used to quickly cut out a bow as both can withstand ring violation on the back. There was no attempt to follow a ring on the back and with power tools, they could be produced rapidly.
They were a low-end bow and hundreds of thousands produced. But, they provided an economical introduction to archery.
Fiber backing was common.
This bow is the one that coined the term "flatbow." When you see the term "flatbow" used historically to specifically define a wood bow, this is it, this what it looks like.